You could probably expand the rest of 11.2 and put it into the binaries folder. The game mode is still fine, so just the editor is affected like the above screenshot.

It appears every driver after Catalyst 11.2 has a bug in Unreal Development Kit. I would have noticed this sooner if I used UDK more often this year. I don’t know how many cards this affects, it might just be for older cards. I’m on a 4870×2.

Anyway the solution is simple, put 11.2’s dx9 dlls into the binaries folder of UDK. Installing the whole 11.2 driver set for the whole system is not a useful workaround, since most people would need fixes or performance gains seen in newer drivers.

For the 32bit editor and game: put atiumdag.dll into \Binaries\Win32For the 64bit editor: put atiumd64.dll into \Binaries\Win64

If you’re using RadeonPro to force crossfire profiles, it will overwrite the dll that you placed, so you’ll have to use the driver version compatibility feature to use 11.2’s dll. I would instead just make a copy of and rename the 32bit UDK.exe into AliceMadnessReturns.exe to get crossfire scaling when launching the game.